The asexual filamentous fungus Aspergillus niger is an important industrial cell factory for citric acid production. In this study, we genetically characterized a UV-generated A. niger mutant that was originally isolated as a nonacidifying mutant, which is a desirable trait for industrial enzyme production. Physiological analysis showed that this mutant did not secrete large amounts of citric a...

The inhibiting effect of ascorbic acid, citric acid and sodium chloride on Polyphenoloxidase (PPO) of Golden Delicious apple cubes was studied. Dipping in ascorbic acid (0.2-10 g/L range) and in NaCl (0.2-1 g/L range) solutions for 5 min increases the PPO activiry. Citric acid solutions (0.2-10 g / L range) have little or no inhibition of PPO. A 90-100% PPO inhibition was obtained with a 5 min ...

introduction: the production of smear layer during canal instrumentation is thought to increase coronal microleakage even after canal obturation. previous studies have shown that the type of irrigant does not necessarily affect the seal of the obturation. our study aimed to evaluate the effect of three irrigation solutions (mtad, citric acid and edta/naocl) on the coronal microleakage of root c...

citric acid and tetracycline hcl are the most common clinical root demineralization agents used in periodontal practice. in this comparative in vitro study the effects of nd: yag laser radiation on root surface was compared to that of citric acid and tetracycline hcl using sem. a total of twenty-one freshly extracted periodontally diseased single rooted premolar teeth were root planned in vitro...

this experiment was conducted to investigate the effect of phytase superdoses alone or in combination with citric acid (ca) in canola meal-based diets severely limited in available phosphorus (pa) on growth performance, plasma phosphorus (p), and tibia ash (ta) in broilers from 22 to 42 d of age. two hundreds and eighty 21-d-old male broilers were used in 28 pens of 10 birds per each. the exper...

modifying polyester spacer fabric by β-cyclodextrin produces a new product with outstanding characteristics. citric acid is used as a crosslinking agent for improvement of durability of this material in textile fabrics. in this research different concentrations of citric acid and β-cyclodextrin were applied on a 3d fabric and some properties including weight change, weight of moisture residue, ...

introduction: the aim of this in vitro study was to evaluate the effect of 10% citric acid and 17% ethylenediaminetetraacetic acid (edta) irrigating solutions on the surface morphology of young and old root dentin by determining the number and diameter of dentinal tubules using scanning electron microscopy (sem). methods and materials: fifty healthy human teeth collected from young (≤30 years) ...

28 Fenton’s reagent, a solution of hydrogen peroxide and ferrous iron catalyst, is used for an 29 in-situ chemical oxidation of organic contaminants. Sulfuric acid is commonly used to 30 create an acidic condition needed for catalytic oxidation. Fenton’s reaction often involves 31 pressure buildup and precipitation of reaction products, which can cause safety hazards 32 and diminish efficiency....